PDA Technical Glossary
PDA Technical Reports are highly valued membership benefits because they offer expert guidance and opinions on important scientific and regulatory topics and are used as essential references by industry and regulatory authorities around the world. These reports include terms which explain the material and enhance the reader’s understanding.
The database presented here includes the glossary terms from all current technical reports. The database is searchable by keyword, topic, or by technical report. Each definition provided includes a link to the source technical report within the PDA Technical Report Portal.
(Please select "All" to restart a filtered Search)
Refine Results
Filter By Technical Report Number
- TR 84: Integrating Data Integrity Requirements into Manufacturing & Packaging Operations (8)
- TR 80: Data Integrity Management System for Pharmaceutical Laboratories (7)
- TR 45: Depth Filtration (6)
- TR 60: Process Validation (5)
- TR 70: Cleaning/Disinfection Programs (5)
- TR 51: Biological Indicators (4)
- TR 57: Analytical Method Validation (4)
- TR 26: Sterilizing Filtration of Liquids (4)
- TR 48: Moist Heat Sterilizer Systems (3)
- TR 1: Validation: Moist Heat (3)
- TR 3: Validation: Dry Heat (3)
- TR 14: Validation: Protein Purification Chromatography (3)
- TR 88: Microbial Data Deviation Investigations in the Pharmaceutical Industry (3)
- TR 76: Identification and Classification of Visible Nonconformities in Elastomeric Components and Aluminum Seals for Parenteral Packaging (3)
- TR 54-5: Quality Risk Management for the Design, Qualification, and Operation of Manufacturing Systems (3)
- TR 54-2: QRM: Packaging Labeling (2)
- TR 56: Phase Appropriate cGMP Application (2)
- TR 57-2: Analytical Method Development (2)
- TR 58: Temp Controlled Distribution (2)
- TR 61: Steam in Place (2)
- TR 67: Objectionable Microorganisms (2)
- TR 68: Drug Shortage Management (2)
- TR 69: Bioburden/Biofilm Management (2)
- TR 74: Reprocessing of Biopharmaceuticals (2)
- TR 13: Environmental Monitoring (2)
- TR 15: Validation: TFF in Biopharmaceuticals (2)
- TR 86: Industry Challenges and Current Technologies for Pharmaceutical Package Integrity Testing (2)
- TR 29: Validation: Cleaning (2)
- TR 41: Virus Filtration (2)
- TR 42: Validation: Protein Manufacturing (2)
- TR 43: Glass Defects (2)
- TR 47: Virus Spikes/Virus Clearance (1)
- TR 49: Validation: Cleaning Biotech (1)
- TR 53: Stability Testing New Drug Products (1)
- TR 54: QRM:Manufacturing Operations (1)
- TR 54-3: QRM: Drug Products (1)
- TR 54-4: QRM: Biotech Drug Substance (1)
- TR 71: Emerging Methods for Virus Detection (1)
- TR 38: Manufacturing Chromatography Systems Postapproval Changes (ChromPAC) (1)
- TR 79: Particulate Matter Control in Difficult to Inspect Parenterals (1)
- TR 30: Parametric Release (1)
- TR 77: The Manufacture of Sterile Pharmaceutical Products Using Blow-Fill-Seal Technology (1)
- TR 44: QRM: Aseptic Processes (1)
Filter By Technical Report Keyword
- Manufacturing (57)
- Quality Risk Management/QRM (38)
- Validation (33)
- Biotechnology (27)
- GMP/Good Manufacturing Processes/cGMP (27)
- Microbiology (20)
- Sterile Processing (20)
- Technology Transfer (18)
- Filtration (11)
- Packaging Science (11)
- Supply Chain (4)
- Visual Inspection (4)
- Outsourcing (3)
- Virus (2)
- Inspections (1)
- Prefilled Syringes/PFS (1)
Filter By Technical Report Category
Diavolume (DV)
A volume equal to the retentate volume to which a diafiltration buffer is added. (TR15)
Source:
Differential Pressure
The difference in pressure between the upstream (feed or influent) and downstream (effluent) sides of the filter. (May be modified with the terms: applied, available differential pressure, clean differential pressure, dirty differential pressure, initial differential pressure, or maximum differential pressure). [Synonym: Delta P (Δ P), PSID, Pressure Drop] (TR45) (TR26)
Source:
Difficult-to-inspect Parenterals (DIP)
When the nature of the product or package limits the ability to perform a thorough inspection for particles. (TR79)
Source:
Diffusion Flow Test
A test to determine the integrity of a filter. The test is based on the measurement of the diffusive (diffusional) flow of a gas through a wetted filter, along with any bulk flow of gas through open (unwetted) pores. Either the gas flow or the downstream liquid, displaced by the gas flow, may be measured. [Synonym: Forward Flow Test] (TR45)
Source:
Diffusion Test (or Forward Flow Test)
A test for membrane integrity that involves measuring the rate of gas diffusion through a liquid-wetted membrane.(TR15) An integrity test in which a filter is subjected to differential gas pressures below the bubble point and gas molecule migration through the water-filled pores of a wetted membrane is measured. This behavior follows Fick’s Law of Diffusion (i.e., the gas diffusional flow rate for a filter is proportional to the differential pressure and the total surface area of the filter). (TR41)
Source:
Diffusive Flow
The movement of a dissolved gas across a liquidwetted membrane based on the concentration (e.g., gas pressure) differential. (TR26)
Source:
Diffusive/Forward Flow Test
A test to determine the integrity of a filter. [Synonym: diffusive flow test, forward flow test.] (TR26)
Source:
Dimensional Product Quality
The product conforms to the required drawing dimensions. (TR43)(TR76)
Source:
Direct Flow Filtration (DFF) or Normal Flow Filtration (NFF)
In direct flow filtration, all fluid is directed through the membrane in a single pass. (TR41)
Source:
Direct Interception
Particles with diameters larger than the filter pore diameter that are prevented from passing through the filter. (TR26)
Dirty Hold Time
The time from the end of product manufacturing until the beginning of the cleaning process (also called “soiled hold time”). (TR29)
Source:
Discrete Control Valve
A device designed for on/off operation; fully opened or fully closed. (TR48)
Source:
Disinfectant
A chemical or physical agent that reduces, destroys, or eliminates vegetative forms of harmful microorganisms but not spores. (TR70)
Source:
Disinfection
The destruction of pathogenic and other kinds of microorganisms by thermal or chemical means. (TR51) (TR70) Process of eliminating nearly all recognized pathogenic microorganisms but not necessarily all microbial forms (e.g., bacterial spores) on inanimate objects. (TR69) The chemical or physical inactivation of a bioburden on inanimate surfaces. Typically this requires a minimum three-log (3-log) reduction of vegetative microorganisms and two-log (2-log) reduction for bacterial spore be achieved in validation. (TR13)
Source:
Distribution
Transport of a medicinal product from a drug manufacturer’s warehouse/storage facility to distribution centers, commercial customers, or clinical facilities. Subsequent distribution may also occur. (TR39) Movement of product within a designated supply chain, including activities that range from preparation for shipment to receipt of the product at the final destination.(TR58)
Distribution Temperature
The temperature range, supported by stability studies, within which a medicinal product can be transported for a short duration of time without adverse effect on quality parameters. (TR39)
Distribution Testing
Qualification of packaging components for physical distribution integrity like shock, vibration, and drop tests. (TR58)
Source:
Distribution Thermocouple
Device placed in the interior of the controlled environment space (CES) to measure air temperature but is not placed in the product (see penetration thermocouple). (TR64)
Documentation
See Development Reports , Process Characterization Report , Process Validation Protocol, or Process Validation Report (TR14) (TR42)
Downstream
Refers to the demand side of the supply chain. Downstream consists of one or more companies or individuals who participate in the flow of goods and services moving from the manufacturer to the final user or consumer. This is the opposite of upstream. (TR46)
Downstream Side (of Filter)
The effluent side of the process step (filter). (TR45) The filtrate or outlet side of the filter. (TR26)
Source:
Drug Development
A general term used to define the entire process of bringing a new drug to the Market. It includes drug discovery, process and product development, pre-clinical research (microorganisms/cell culture/animals) and Clinical trials (on humans). (TR56)
Source:
Drug Product (DP)
A pharmaceutical product type that contains a drug substance, generally, in association with excipients. [Synonym: Dosage Form; Finished Product] (TR57)(TR14)(TR42)
A finished dosage form (e.g., tablet, capsule, or solution) that contains a drug substance, generally, but not necessarily, in association with one or more other ingredients.(TR38) (TR67) (TR88)
The dosage form in the final immediate packaging intended for marketing.(TR60)(TR82)
Source:
Drug Shortage Prevention & Response Plan
A document that provides a structured action plan to proactively prevent drug shortages and also respond to a shortage in the event that one occurs. (TR68)
Source:
Drug Shortage Risk Register
A single source of information on risks that can result in drug shortages, associated risk levels, risk control actions with owners, status, due dates and residual risk after appropriate risk control actions have been taken. (TR68)
Source:
Drug Substance (DS)
The active ingredient that is subsequently formulated with excipients to produce the drug product. It can be composed of the desired product, product-related substances, and product- and process-related impurities. It may also contain excipients, including buffers and other components. [Synonyms: bulk drug substance, bulk material, active pharmaceutical ingredient (API)] (TR14) (TR57) (TR74) (TR60)
Active pharmaceutical ingredient in a drug product that is responsible for that product’s therapeutic activity.(TR67) (TR82) (TR88)
See Active Pharmaceutical Ingredient (API). (TR56)
Source:
Dry Equipment
No visible water in the equipment or line when viewed under appropriate lighting conditions. (TR29) No visible water pool evident in the equipment or line when viewed under appropriate lighting conditions. (TR49)
Dryness Fraction
An absolute measure of the actual latent heat of a sample of steam relative to the theoretical latent heat of saturated steam. (TR01) (TR48)
Source:
Dryness Value
A dimensionless test quantity developed to approximate the dryness fraction. (TR01)
Source:
Dwell Time
The period that items are subjected to a given processing condition. [Synonym: Residence Time] (TR3)
Source:
Dynamic (in operation)
BFS machine line fully operational and filling, with the number of allowed operating personnel present as during normal running conditions. (TR77)
Source:
Dynamic Light Scattering (DLS)
A technique used to measure the size and size distribution of particles. Particles suspended in a solution will cause scattering of light and the extent of the scattering is related to the size and shape of the particles. (TR47)
Source:
Dynamic Monitoring
Monitoring of an environment during normal operations, that is, when the usual equipment is operating and personnel are present, and the process or simulated process is ongoing. Per the EU and ISO documents this is synonymous with operational condition (including the equipment operating and personnel present). (TR13)
Dynamic Record Format (FDA)
The record format allows interaction between the user and the record content.(TR80)
Source:
Dynamic Record Format (MHRA)
An electronic record which the user reviewer can interact with.(TR80)
Source:
Dynamic Record Format (WHO)
Records, such as electronic records, that allow for an interactive relationship between the user and the record content.(TR80)